def reverseBetween(self, head, m, n):
"""
:type head: ListNode
:type m: int
:type n: int
:rtype: ListNode
"""
if not head or m >= n:
return head
dummy = ListNode(0)
dummy.next = head
head = dummy
for i in xrange(1, m):
if not head:
return None
head = head.next
last = head.next
for i in xrange(m, n):
if not head:
return None
tmp = last.next
last.next = tmp.next
tmp.next = head.next
head.next = tmp
return dummy.next
def deleteDuplicates(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
if not head:
return head
dummy = ListNode(0)
dummy.next = head
while head and head.next:
if head.val == head.next.val:
head.next = head.next.next
else:
head = head.next
return dummy.next
def swapPairs(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
if not head or not head.next:
return head
dummy = ListNode(0)
dummy.next = head
pre = dummy
while pre.next and pre.next.next:
t = pre.next.next
pre.next.next = t.next
t.next = pre.next
pre.next = t
pre = pre.next.next
return dummy.next
def reverseKGroup(self, head, k):
"""
:type head: ListNode
:type k: int
:rtype: ListNode
"""
if not head or k <= 1:
return head
dummy = ListNode(0)
dummy.next = head
pre = dummy
count = 0
while head:
count += 1
if count % k == 0:
pre = self.reverse_list(pre, head.next)
head = pre.next
else:
head = head.next
return dummy.next
def sortedListToBST(self, head):
"""
:type head: ListNode
:rtype: TreeNode
"""
if not head:
return head
dummy = ListNode(0)
dummy.next = head
pre = dummy
slow = head
fast = head
while fast and fast.next:
fast = fast.next.next
slow = slow.next
pre = pre.next
mid = TreeNode(slow.val)
mid.right = self.sortedListToBST(slow.next)
pre.next = None
mid.left = self.sortedListToBST(dummy.next)
return mid
def removeNthFromEnd(self, head, n):
"""
:type head: ListNode
:type n: int
:rtype: ListNode
"""
if not head or n < 1:
return head
dummy = ListNode(0)
dummy.next = head
pre = dummy
length = 1
while length < n:
length += 1
head = head.next
while head.next:
head = head.next
pre = pre.next
pre.next = pre.next.next
return dummy.next
def rotateRight(self, head, k):
"""
:type head: ListNode
:type k: int
:rtype: ListNode
"""
if not head or k < 1:
return head
k %= self.get_length(head)
dummy = ListNode(0)
dummy.next = head
head = dummy
for _ in range(k):
if head is None:
return null
head = head.next
pre = dummy
while head.next:
head = head.next
pre = pre.next
head.next = dummy.next
dummy.next = pre.next
pre.next = None
return dummy.next
class Solution(object):
def deleteDuplicates(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
if not head:
return head
dummy = ListNode(0)
dummy.next = head
head = dummy
while head and head.next and head.next.next:
if head.next.val == head.next.next.val:
val = head.next.val
while head.next and head.next.val == val:
head.next = head.next.next
else:
head = head.next
return dummy.next
s = Solution()
l1_1 = ListNode(1)
l1_2 = ListNode(1)
l1_3 = ListNode(1)
l1_4 = ListNode(2)
l1_5 = ListNode(3)
l1_1.next = l1_2
l1_2.next = l1_3
l1_3.next = l1_4
l1_4.next = l1_5
print s.deleteDuplicates(l1_1)
head = head.next
pre = dummy
while head.next:
head = head.next
pre = pre.next
head.next = dummy.next
dummy.next = pre.next
pre.next = None
return dummy.next
def get_length(self, head):
count = 0
while head:
head = head.next
count += 1
return count
s = Solution()
l1_1 = ListNode(1)
l1_2 = ListNode(2)
l1_3 = ListNode(3)
l1_4 = ListNode(4)
l1_5 = ListNode(5)
l1_1.next = l1_2
l1_2.next = l1_3
l1_3.next = l1_4
l1_4.next = l1_5
print s.rotateRight(l1_1, 2)
l1_1.next = None
print s.rotateRight(l1_1, 1)
if not head:
return head
first = ListNode(0)
first_head = first
second = ListNode(0)
second_head = second
while head:
if head.val < x:
first_head.next = head
first_head = first_head.next
else:
second_head.next = head
second_head = second_head.next
head = head.next
second_head.next = None
first_head.next = second.next
return first.next
s = Solution()
l1_1 = ListNode(1)
l1_2 = ListNode(4)
l1_3 = ListNode(3)
l1_4 = ListNode(2)
l1_5 = ListNode(5)
l1_6 = ListNode(2)
l1_1.next = l1_2
l1_2.next = l1_3
l1_3.next = l1_4
l1_4.next = l1_5
l1_5.next = l1_6
print s.partition(l1_1, 3)
head.next = new_head
new_head = head
head = tmp
return new_head
def compare(self, l1, l2):
while l1 and l2:
if l1.val != l2.val:
return False
l1 = l1.next
l2 = l2.next
return True
s = Solution()
l1_1 = ListNode(1)
l1_2 = ListNode(2)
l1_3 = ListNode(3)
l1_4 = ListNode(4)
l1_5 = ListNode(5)
l1_1.next = l1_2
l1_2.next = l1_3
l1_3.next = l1_4
l1_4.next = l1_5
print s.isPalindrome(l1_1)
l2_1 = ListNode(1)
l2_2 = ListNode(2)
l2_3 = ListNode(3)
l2_4 = ListNode(2)
l2_5 = ListNode(1)
l1 = l1.next
l2 = l2.next
l = l1 or l2
while l:
cur = l.val + res
res = cur / 10
cur_Node = ListNode(cur % 10)
first.next = cur_Node
first = first.next
l = l.next
if res:
first.next = ListNode(res)
return ans.next
s = Solution()
l1_1 = ListNode(2)
l1_2 = ListNode(4)
l1_3 = ListNode(3)
l2_1 = ListNode(5)
l2_2 = ListNode(6)
l2_3 = ListNode(4)
l1_1.next = l1_2
l1_2.next = l1_3
l2_1.next = l2_2
l2_2.next = l2_3
s.addTwoNumbers(l1_1, l2_1)
